Seamless Data Distribution System
http://www.webgis.com/usgsseam.html

USGS

This site from the USGS and the EROS Data Center (EDC) presents the Seamless Data Distribution System (SDDS). The site is the ultimate location for exploration and data retrieval from both the United States and international locations. The site features free data downloads, user defined datasets and area, data acquisition from different government hosts, and elevation point and profile tools.

This resource is referenced here:

• Cutting Edge:Courses:GIS and Remote Sensing: Remote Sensing Data
• Cutting Edge:Develop Program-Wide Abilities:Geoscience in the Field:Activities: Mapping Bedrock Outcrops with Stride & Compass and a GPS Unit in a soil and forest mantled landscape
• Starting Point-Teaching Entry Level Geoscience:Undergraduate Research:Examples: Watershed Analysis
• Integrating Research and Education:Teaching with GeoPads: Topographic Data Resources
• Cutting Edge:Courses:GIS and Remote Sensing: Topographic Data
• Starting Point-Teaching Entry Level Geoscience:Teaching with GIS: Creating Topic-Specific Maps

Subject: Geoscience:Geology
Resource Type: Audio/Visual:Images/Illustrations, Maps, Datasets and Tools:Tools, Datasets
Data Derived: Data Derived
Data Source: Observational Data
Science Background Required: Basic scientific background required